The long-term goal of this SBIR proposal is to develop transgenic tobacco as a cost-effective bioproduction system for human glcocerebrosidase (hGCase). Enzyme replacement using hGCase is the most effective current therapy for Gaucher disease but its supply from human placenta is limited and its cost per patient is prohibitive. Transgenic tobacco has the potential to produce an effective hGCase product at significantly lower development and production costs. The aim of Phase I is to teat the ability of tobacco plant cells to express hGCase. Specific objectives are 1) to generate hGCase cDNA's and engineer them into plant transformation/expression vectors, and 2) to introduce the hGCase DNA into tobacco cells and monitor transgene expression and hGCase production. Success in these objectives would support continued Phase II research aimed at optimizing production of bioactive hGCase in transgenic tobacco. New technology developed as part of this project could, additionally be applied to plant bioproduction of other pharmaceuticals.